Question

Which of the following cases, a rigid body, necessarily has an angular acceleration.

• A. Line of action of force is parallel to Axis of rotation
• B. Line of action of force is perpendicular to the axis of rotation
• C. Line of action of the force is perpendicular and skew to the Axis of rotation
• D. Line of action of the force intersects the axis of rotation

Answer 1

The correct option is C

Line of action of the force is perpendicular and skew to the Axis of rotation

For a body to have an angular acceleration there should be some net torque about any axis considered.

Solution: If the force is perpendicular but its line of action intersects the Axis of rotation then it cannot produce any angular acceleration about the given and constrained "Axis of rotation”. i.e., |$\overrightarrow{T}$| = 0